Southbend broken bolt problem please help

[bhop]

So i had "friend" who helped me move to my new house decide that while I was at work he would assemble my old southbend lathe for me. Long story short he broke one of the headstock bolts off. I tried an easy out which broke off in the hole in the bolt then trying to shatter the easy out I managed to break the tip of a punch off on top of that ( still not sure how I managed that one) I've tried penetrating oil, drilling, using dremel grinding stones and diamond tip bits and have only made a small crater in it. The way that it is going into is a reverse v which makes me kinda nervous. Did I mention it's in a blind hole? I don't have any way to use a small carbide end mill which is the only thing I can think of that would get it out. How would you go about getting this bolt out?

[lancem]

if it is a part you can remove and take some where I would look for a shop that does EDM and have them remove it, might be a little pricey but looks to me like you're choices are few now.

[Pipefitter]

Spring loaded center punch, use an adjustable force type. Keep working at it in a counterclockwise direction. I have removed more broken bolts this way than using easy-outs.

[country gent]

I use a dull prick punch and small ball peen to walk them out get a solid prick on the edge and work counterclockwise tapping with hammer on angled punch. I a big bolt a small chiesel can be used but the punch has normally worked better for me. Otherwise carbide tooling or edm is going to be needed. finding an edm big enough for the head stock is going to be hard and getting all the dielectric fluid out of the head stock may be a issue. If possible use a left hand drill as cutting may grab and back out also. Annealing the hardened steel may help depending where its at may help

[Grendl]

Try putting a bit of heat to the bolt and its surrounding metal, do not make it red hot , 300-400 hundred degrees is enough and touch a dab of beeswax to the bolt threads and let it penetrate and then use any one of the punch methods to remove. this trick has removed my bacon from the fire a number of times (it pays to watch old guys work on old machines,tractors and such). Try to remove the bolt before it cools back to ambient temp. Rinse and repeat as needed.
Rick

[oldred]

Wow, that's a tough one! That trick Pipefitter suggested with the springloaded center punch works really well, as does the suggestion of a bit of heat and the Beeswax. The problem here is this sounds like far more than just a stuck bolt and by now I would imagine the threads are a bit buggered up. Why did the bolt break in the first place? Did it bottom out and then break from over-torquing or did it just go in really tight and bind before breaking? Either way will mechanically lock the pieces in so if either is the case it's not likely penetrating lube or tapping it will loosen it and drilling may be your only option.

How big is this hole and how far below the surface is the broken bolt? I have had good success by welding a nut or another bolt onto the piece and get them out that way if the broken part is near flush with the surface but the welder had better know EXACTLY what he is doing if you try that one.

[bangerjim]

Before you broke off your entire tool collection in the bolt (!!), I would have just simply step-drilled it out, cleaned out the remains of the broke bolt, and re-tapped it to the same or larger size.

You are now in for some real fun!


bangerjim

[M-Tecs]

I have used these with good results


http://www.use-enco.com/1/1/56226-od-set-1-omegadrill-tap-extractor-drill-sets.html

http://www.use-enco.com/1/1/96654-omegadrill-solid-carbide-tap-extractor-drills.html

http://www.mscdirect.com/browse/tn/Threading/Tap-Extractor-Drills?searchterm=broken+tap+removal&navid=4287920392

[bhop]

The punch method was actually the first thing I tried I have not tried any heat because I figured that the ways were hardened and I didn't want to screw them up I just went and bought some left-handed drills to try that

[bhop]

http://i1099.photobucket.com/albums/g390/Bhop84/F4679D25-AC96-4AE9-8226-0B1ED594956B_zpsmajithqo.jpg (http://s1099.photobucket.com/user/Bhop84/media/F4679D25-AC96-4AE9-8226-0B1ED594956B_zpsmajithqo.jpg.html)

[bhop]

This is the old southbend
http://i1099.photobucket.com/albums/g390/Bhop84/CC37D1C0-F7A9-4B3C-A695-154CACE64876_zpsybjfngx6.jpg (http://s1099.photobucket.com/user/Bhop84/media/CC37D1C0-F7A9-4B3C-A695-154CACE64876_zpsybjfngx6.jpg.html)

[owejia]

You might try a magnetic base portable drill. Maybe a tool rental place has one for rent. I've used them as portable boring machines when I had my machine shop. If you can get your hands on a portable magnetic drill, a carbide drill bit will drill it right out. I believe the ways on those old lathes are cast iron so a little heat should not damage or warp it.

[oldred]

The carbide bit is a good idea but be warned that when using one with a hand held drill they can break like glass! Considering what this is and the need to keep damage to a minimum that mag drill is a darn good idea with a carbide bit. From that pic I can't tell is the piece of easy out is still in that thing or not, is that the piece of the broken punch tip that's visible there with the easy out hidden under that? If so then the punch tip should be "drilliable" (is drilliable even a word???) but it likely will start spinning as the drill grips it, most likely it's mushroomed at the end and rather tight so if you drill with one of those left hand bits it may spin out of there. The easy out however is not likely to drill with a regular HSS drill bit but probably a cobalt bit will do the trick, easy outs aren't nearly as hard as a tap.

[JSnover]

When all else fails carbide is your friend but go easy until you get the hole cleaned up. Oldred was right; they break like glass.
Buy more than one. You might even try to dress things up with a round carbide bur, first.

[bangerjim]

I gave a friend about 20 number size carbide drills with 1/8" shanks (circuit board drills).

Of course he immediately whipped out his trusty "Dremel tool" and broke all of the within a week!!!!!

As said, carbide is excellent tooling, but it MUST NOT be used in any hand-held drill!!!!

I have several sets of carbide drills 1/4" thru #70 and always use them in a sensitive drillpress. Have never broke one in many years.

Hope you get your stud out.

banger

[owejia]

Cheap concrete carbide drill bits work if you can spin them fast enough. A little heat up to about lead melting temp. will anneal the hardened easy out and after it cools down you should be able to drill it out, had a machine shop, manufactured and also repaired just about anything, so have had lots of experience with removing broken bolts. Also used a magnetic base drill as a portable boring machine, on heavy equipment mostley.

[Bent Ramrod]

I have sometimes been able to wear a sufficient sized hole in a broken bolt or tap with dental burrs in a Dremel tool. It was always a long, mean job with lots of dull burrs at the end, but eventually the hole was big enough to either get some kind of purchase on it, or to enable the rest of the threaded part to be collapsed into it and broken out.

The burrs come in little plastic boxes of six. I buy mine at gun shows.

[Artful]

Got Harbor Freight?
http://www.harborfreight.com/20-pc-carbide-rotary-micro-bit-assorted-set-62379.html

[bob208]

will the hole hurt any thing if it does go through ? if not can you get to the back side ? if you can lay out the hole and drill from the back side most times the bit will catch and spin it right out. I have used this method many times.


not trying to give you hard time but throw those easy outs away. they are not easy nor do they get the bolt out. you would be better served to have a set of left hand drill bits. another way we used to do it was a masonry bit and reverse grind it to cut left hand that works on old rusted and hard bolts.

another tid bit I learned was I you drill out a bolt and there is still some junk in the threads. do not use a starting or plug tap. chase the threads with a bottom tap. the bottom tap will push the junk out. the other two the junk will wedge in the taper and then you will have a broken tap to deal with.

[JSnover]

"tried penetrating oil, drilling, using dremel grinding stones and diamond tip bits and have only made a small crater in it."

The most tedious and important part is getting rid of all the broken pieces. Every time your drill catches one, there's a good chance of breaking it. The grind stones and burrs are probably best for that. After you get all the scrap metal out of the hole things should get easier. I wouldn't bother any more with hammers and punches if it simply will not budge. The more you pound, the more you work-harden the piece.

[bangerjim]

All you are doing with hammers and punches is expanding the bolt in the hole! It will be really wedged in there after a round with those tools.

[M-Tecs]

These do work as claimed http://omegadrill.com/wst_page3.html

Q: How is it possible to actually cut a HSS tap that is hardened to around 65 Rockwell C?
- Well, it's not easy but the Omegadrill can actually do it! Omegadrills are produced from revolutionary grade of sub-micron carbide produced to an exact formulation that results in a carbide grade that is extremely durable to handle the abuse of drilling through something as hard as a tap. We then grind a very unique point geometry on Omegadrill's - that gives the drill the strength to cut all the way down through the tap.

Q: What type of equipment is needed to use Omegadrills?
- Omegadrills are designed to be used on either a Machining Center or a Milling Machine. The most common machine used is probably a "Bridgeport" type Knee Mill. In some cases a magnetic drill press can be used – and it will probably need to be run at maximum RPM. Some people with extra large biceps have used the two largest sizes of Omegadrills with a portable hand drill. If using a hand drill is the only option then run at least 1,200 RPM, and keep and much feed as possible on the Omegadrill without allowing any deflection.

Q: If Omegadrills can cut through a broken tap then what other difficult drilling operations can they do?
- Omegadrills have been used to remove broken E-Z Outs / Screw Extractors, broken twist drills, broken / seized dowel pins, and of course they can be used to drill out broken screws and bolts without any problems. Omegadrill's can also be used to drill holes in extremely hard materials such as stellite, chilled cast iron, hardened steel and even ceramic tiles. We even had a customer tell us he used an Omegadrill to drill a hole in a granite surface plate!

Q: Are their any special techniques for using Omegadrills?
- It's good to keep in mind that removing broken taps is not an easy thing to do.
The two most critical appliction factors are....

1) Make sure the Omegadrill starts off drilling straight. Omegadrills are solid carbide, a material that does not handle very much deflection. In order to start off drilling straight the Omegadrill needs as flat a entry surface as possible. This is why we recommend "knocking" the broken top off the tap and spotting the tap with as large an Omegadrill as possible. If the top of the tap is down inside the hole, use a small diameter carbide burr, or a small endmill to cut away the jagged top of the broken tap.

2) Solid carbide tools work best with as rigid a set-up as possible. Many people find the drilling works best on a Knee Mill if they lock the quill and feed the drill using the knee handle. On a machining center, use the hand wheel / pulse generator and feed the drill using the lowest setting possible (probably .0001") and feed with very steady and constant feed. If you're in a situation where you can only feed by hand with a quill, then tighten the quill lock slightly, to create some drag, and feed with steady and even pressure.

[bhop]

I have a few more things to try now thank you guys. I'll update after I've got it out or exhausted all the suggestions

[EDG]

If you have a lot of patience find a diamond burr with a long shank.

Make a drill guide or drill jig plate with a hardened bushing to fit the shank of the diamond burrs.

You might use a carbide burr instead if it will but the stuff jammed in the hole.

Clamp your drill guide to the lathe bed and start drilling out the junk.

With a good guide to keep the burr in the center you will eventually be able to drill out all the old junk.

Just take your time. Maybe 15 minutes at a time or 15 min a day. Eventually you will get it out.

If you do not feel this is working you can find a shop with one of the old tap disintegrators. Those things will burn out the old ****. Just make sure the guy knows not to damage the casting.

141112


Find another friend. He just wanted to play with your lathe.

[oldred]

EDG, you hit on something that hasn't been covered yet and that's "take your time". Something like this can be a difficult, long and frustrating procedure but getting impatient will likely lead to even more problems. In a case like this where it has become apparent the junk in the hole is not going to come out in one piece then the person needs to resign themselves to the fact they are going to have to "finesse" the pieces out a little at a time. How this is done will depend on each situation but it must be approached with precise procedures chosen with the intent to do the least harm to the part rather than a "just get-er out at all costs" attitude. Often this can mean a long time spent wearing way the offending parts with precision tools and sometimes it even means resorting to substantial expense such as buying/renting specialized tooling or farming out the job to someone else who is so equipped. The cost must be weighed vs the worth of the part and in the case here no effort should be spared doing this properly, personally I think one the best suggestions so far has been to rent a mag drill and drill it out with a carbide bit, but then that's just the way I would do it.

[bhop]

Oldred I agree when it first happened that's how everything got broke off in there I was pissed at the guy and just wanted it out. After the punch broke I decided to walk away from it for a while every other week or so I would grind pieces out or try this or that stopping before I got frustrated. Then I got to the point where I wasn't sure what to try and stopped completely for fear of making it worse til I had a plan. I think there is a mag drill at my work I am going to check tomorrow. I may have to take the motor off the machine to get it on right but so be it. I really appreciate all the useful posts greatly. Trust me this guy will never be back to my house.

[leeggen]

I have done this before, but you must take yuor time. You will have to get the carbide tip drills and slowly drill the junk out. Then get a lefthand drill and start drilling til the drill snagg the bolt. Use some heat and heat the area around the bolt, now comes the worst of it. Get some freon and use the hose and spray it on the bolt, the heat expands the bed and the freon will chill the bolt, at this point GENTLY turn the drill nad back the bolt out. You may need to keep thed freon spraying on the bolt, you will see frost but thaat is good. The bed being large mass it will hold heat the bolt will chill and shrink slightly and should come loose.
Best of luck and a LOT of patients.
CD

[JSnover]

I have removed broken bolts and broken taps by heating and cooling. It takes a lot of patience. Heat, see if you can turn it, then cool and try it again. Keep alternating.
Freon is scarce but my shop always has Dykem Remover on hand. Starting fluid or carb/choke/brake cleaner would also work but make sure the part is clean and dry before applying heat, the room is ventilated, etc.

[oldred]

While I agree heat can be a big help with stuck bolts it appears that the case here is that the piece is mechanically locked into place due to what has happened, there are damaged threads and distorted pieces wedged into the hole and in a situation such as that heat isn't likely to help very much. Probably wouldn't hurt anything if it is practical to get the equipment there to do it but I wouldn't rely too much on it, at least not in this instance. Also you really need a solid carbide drill as opposed to the carbide tipped masonry type bits, the solid carbide bits are a true spiral bit designed for drilling metal and lifting the chips out of the way and will drill a MUCH more precise hole. You don't want a carbide tip wandering around in there ripping out the threads, the idea here is to drill through the broken/stuck parts without doing further damage to the original hole.

[Eddie2002]

Maybe put a piece of dry ice on the area and let it get real cold then heat up the base and dump oil into the hole. The cold might loosen everything up and the oil and heat could break it loose. That's a real tough one you've got there.

[Goatwhiskers]

Don't know if I'm right but have always understood that the ways are of cast iron. If that's the case, you can't cut cast with a torch. I've removed a lot of broken off studs from engine blocks using a torch directly on the steel in the hole, when it hits temp hit the oxygen and the molten steel is blown out with no damage to the iron. Just have to clean out the threads with a tap. Messy but worth a thought. GW

[oldred]

Don't know if I'm right but have always understood that the ways are of cast iron. If that's the case, you can't cut cast with a torch. I've removed a lot of broken off studs from engine blocks using a torch directly on the steel in the hole, when it hits temp hit the oxygen and the molten steel is blown out with no damage to the iron. Just have to clean out the threads with a tap. Messy but worth a thought. GW


That would have been my first suggestion had this not been something like a lathe bed and I have removed quite a few that way but two other things wrong with that here also, first there are several pieces in there with one of them being an easy out which is not likely to cut very well. Second heating that way in just one spot could easily warp the lathe bed due to the uneven heating and if that happens he would be far worse off than he is now. When cutting with a torch either cutting normally or cutting out a bolt such as this the molten metal is NOT "blown" out, it actually burns and unless the material is easily oxidized that trick doesn't work very well and I doubt seriously it would be satisfactory here mostly due to the piece of the easy out.

A cutting torch works by burning the heated metal with the oxygen stream, not by blowing away the molten metal as is sometimes mistakenly thought. Once the iron is ignited the preheat flame can actually be shut off and if held steady enough the cut can continue with just the oxygen alone, when cutting a bolt piece out of a hole it's sometimes helpful to do this to prevent damage to the surrounding metal.

[JSnover]

While I agree heat can be a big help with stuck bolts it appears that the case here is that the piece is mechanically locked into place due to what has happened, there are damaged threads and distorted pieces wedged into the hole and in a situation such as that heat isn't likely to help very much. Probably wouldn't hurt anything if it is practical to get the equipment there to do it but I wouldn't rely too much on it, at least not in this instance. Also you really need a solid carbide drill as opposed to the carbide tipped masonry type bits, the solid carbide bits are a true spiral bit designed for drilling metal and lifting the chips out of the way and will drill a MUCH more precise hole. You don't want a carbide tip wandering around in there ripping out the threads, the idea here is to drill through the broken/stuck parts without doing further damage to the original hole.
All we know is he has a broken bolt. Cross-threaded? Overtorqued? Rusted? Some heating/cooling cycles and a lot of patience have saved me a lot of grief.

[akajun]

Im gonna throw my two cents in here. First, all these people recomending a torch, do not do it. This is a flame hardened precision ground lathe bed and you run the risk of removing the hardening, or releasing stress/ causing a distortion in the bed which will ruin it. NO heat/ welding/ torches.
Second, as good as Kroil is, I dont find it works that well on bolts that have a layer of varnished oil and grease on them like a lathe bed would. I would suggest getting a bit of modelling clay and making a dam the size of the hole and filling it with evapo rust overnight. This will disolve the rust and oil after a few cyles of this and then you can fill with kroil which will now work a little better.
Next, you should totally disassemble the bed, and place it on your mill table. It does not matter if the bed is bigger than your table, just block it up and make sure it is well supported around the broken bolt and clamp it down. You dont want this thing to move at all. Next go after that bolt with a small centercutting carbide endmill, Say 1/4" or so, just make sure it is smaller than the minor diameter of the threads. This will do two things, one it will make the broken end flush where you can evaluate it better to make sure you are in the center of the hole, and you can adjust the x/y table to cut to the bottom of the threads of the bolt. Peck drill with the quill about .001-.002 using the stop and blow out the chips each time with compressed air.
When you think you have most of it out, re center on the hole, start with a quality drill under the tap size for the hole, and begin step drilling. till you have most of it out. If you are lucky, you may find that the reminants of the bolt come out on their own with drilling, if not, take a tap and put it in the chuck and re tap the hole. The tap will find the old threads and pull the bolt pieces out.
Other options are to find someone with a tap burner or large sinker EDM like was shown.

[bhop]

Im gonna throw my two cents in here. First, all these people recomending a torch, do not do it. This is a flame hardened precision ground lathe bed and you run the risk of removing the hardening, or releasing stress/ causing a distortion in the bed which will ruin it. NO heat/ welding/ torches.
Second, as good as Kroil is, I dont find it works that well on bolts that have a layer of varnished oil and grease on them like a lathe bed would. I would suggest getting a bit of modelling clay and making a dam the size of the hole and filling it with evapo rust overnight. This will disolve the rust and oil after a few cyles of this and then you can fill with kroil which will now work a little better.
Next, you should totally disassemble the bed, and place it on your mill table. It does not matter if the bed is bigger than your table, just block it up and make sure it is well supported around the broken bolt and clamp it down. You dont want this thing to move at all. Next go after that bolt with a small centercutting carbide endmill, Say 1/4" or so, just make sure it is smaller than the minor diameter of the threads. This will do two things, one it will make the broken end flush where you can evaluate it better to make sure you are in the center of the hole, and you can adjust the x/y table to cut to the bottom of the threads of the bolt. Peck drill with the quill about .001-.002 using the stop and blow out the chips each time with compressed air.
When you think you have most of it out, re center on the hole, start with a quality drill under the tap size for the hole, and begin step drilling. till you have most of it out. If you are lucky, you may find that the reminants of the bolt come out on their own with drilling, if not, take a tap and put it in the chuck and re tap the hole. The tap will find the old threads and pull the bolt pieces out.
Other options are to find someone with a tap burner or large sinker EDM like was shown.

This would've been my first course of action but unfortunately the only mill I have is the milling attachment for this lathe

[akajun]

This would've been my first course of action but unfortunately the only mill I have is the milling attachment for this lathe

Then your going to have to send it out, Carbide drills in handheld drills, even carbide tipped or spade drills will break.

[oldred]

All we know is he has a broken bolt. Cross-threaded? Overtorqued? Rusted? Some heating/cooling cycles and a lot of patience have saved me a lot of grief.


Not exactly, from the pics and his description this thing has obviously become more than just overtightened even if that was what was wrong to start with. Heat is NOT going to help a mechanically locked bolt such as cross threaded as was mentioned or one that is stuck from mangled theads nor is it likely to help remove a piece stuck from being bottomed out, in this case the piece has been drilled, has a piece of easy out stuck in it along with a piece of a punch wedged on top of that and it has been mushroomed and the top threads ruined from previous attempts, heat (even if it could be used here) is very unlikely to help this situation. Heat can help with tight threads due to slight malformations, rust or just simply overtorqued but in any situation where just a tiny expansion of a VERY few thousandths is not going to release the stuck part then it's simply not going to help.

Cut the bolt out with a torch? Heat it with a torch (Think about how hot it would have to get)? Good gosh people this is a lathe bed we are talking about here!

That excellent post by akajun reads like a "how-to" from a pro and is a detailed description of the right way to do this! At this point there is only minor damage to that lathe bed but that can easily turn into a major problem or even destruction of this fine old machine. To do this right is probably not going to be simple and maybe even somewhat costly but considering the need to minimize the damage to an absolute minimum it would seem the thing to do. For sure heating&beating on this thing is not the right approach!

[bhop]

Not exactly, from the pics and his description this thing has obviously become more than just overtightened even if that was what was wrong to start with. Heat is NOT going to help a mechanically locked bolt such as cross threaded as was mentioned or one that is stuck from mangled theads nor is it likely to help remove a piece stuck from being bottomed out, in this case the piece has been drilled, has a piece of easy out stuck in it along with a piece of a punch wedged on top of that and it has been mushroomed and the top threads ruined from previous attempts, heat (even if it could be used here) is very unlikely to help this situation. Heat can help with tight threads due to slight malformations, rust or just simply overtorqued but in any situation where just a tiny expansion of a VERY few thousandths is not going to release the stuck part then it's simply not going to help.

Cut the bolt out with a torch? Heat it with a torch (Think about how hot it would have to get)? Good gosh people this is a lathe bed we are talking about here!

That excellent post by akajun reads like a "how-to" from a pro and is a detailed description of the right way to do this! At this point there is only minor damage to that lathe bed but that can easily turn into a major problem or even destruction of this fine old machine. To do this right is probably not going to be simple and maybe even somewhat costly but considering the need to minimize the damage to an absolute minimum it would seem the thing to do. For sure heating&beating on this thing is not the right approach! I agree. I didn't know if I was missing something before making the decision to tear it down and have to move this heavy beast

[oldred]

I'm going to stray a bit from the original subject and talk about easy-outs in general -or "never-outs"- as I like to call them since for me they rarely ever worked, I say "worked" because I don't have them in my shop anymore! They may be ok for something that's not very tight to start with but in those cases there are other, and IMO mostly better, means of removal. It just seems to me that the principle behind the way these things work (supposed to work) is just counterproductive, being tapered they tend by their very design to expand the broken part and make it tighter in the hole with the spiral type getting ever tighter the more torque is applied to it! If a broken fastener is not overly tight to start with then maybe these things can work as long as the wedge type is not driven in to hard or the fastener part breaks loose before the spiral type has a chance to start expanding the part, still if the piece is not stuck any worse than that then other means may be more appropriate. This is of course only my opinion and YMMV but for me I choose not to even have the darn things in my tool box anymore!


About the only real use I can easily think of for these things is IF a part is broken deeply into the hole making it inaccessible to most any other tool except a drill and IF it's not so tight that the easy-out can get sufficient grip without having to expand the part then maybe it will be useful, still if it's loose enough to come out without expanding the part then a left hand drill will usually work just as well or better.

[MtGun44]

For FUTURE REFERENCE, not applicable at this point in the disaster. I think you need
to take the lathe apart and get the bed to a machine shop with a mill to drill it with
a cabide bit. Otherwise you are going to be in trouble.

Isn't help from "friends" wonderful? Take all your easy outs and throw them away.

Left handed drills are THE MOST RELIABLE way to remove broken bolts. I will NEVER,
EVER again put an "easy out" (NEVER OUT?) into a broken bolt again. Start with a small,
NEW and SHARP drill and get a perfect centerpunch, then get your first, small, perhaps 1/8"
on a 3/8" bolt, hole drilled.

Now - switch to left handed drills and start drilling with one size and then the next larger
in the set. Eventually, you will have relieved enough of the stress by hollowing out the
stub AND the left handed drill bit will grab and the stub will suddenly spin up out and
be free.

REALLY - I have done this a bunch of different ways and DO NOT use easy outs and
DO buy a left handed drill bit set. Of course, they run backwards so you need a
reversible drill. THE solution.

[Walter Laich]

I'm totally ignorant on all of this so help me out with a question:
.
why not just drill out to a larger size and retap the hole? Want to learn here, not be a smart-a$$

[oneokie]

The big issue is the broken ezeout and punch that are in the broken bolt at present.

[JSnover]

Generally best to save the existing thread if you can. In this case a larger bolt may not be an option.

[Walter Laich]

could you come in from other side?

[bhop]

no its a blind hole and to drill from other side would mean drilling through about 6" of the bed and thats a no go because that would weaken it way too much

[Walter Laich]

thanks--shows you what I don't know
good luck with this.

[bob208]

two weeks. by now I would have found a place to edm it out.

[bob208]

two weeks. by now I would have found a place to edm it out. some times you have to belly up to the bar and pay the price.

[bhop]

two weeks. by now I would have found a place to edm it out. some times you have to belly up to the bar and pay the price.
well considering i work 11 hours a day 5 days a week i really only have had 4 days to work on it. much less tear the whole thing apart to be able to load it up. today was actually supposed to be my day off but guess where im writing this post at, yep at work.

[bob208]

I was not trying to give you a hard time. just stating from my point of view. to me the lathe being out of service for two weeks would cost me more then paying to get the job done.

[bhop]

Ok my bad. I have another lathe so I can still get stuff done

[Walter Laich]

any up-date?

[bhop]

not yet i havent had a day off in almost a month

[Cap'n Morgan]

Drill & tap a new hole next to the old one. Life is too short to fiddle away on a broken bolt...

[oldlongbeard]

1. Take pencil grinder with carbide flat burr/endmill. Get the top of what is left in there as flat as you can.
2. Make a mild steel tube as thick wall as you can, and still get a welding rod inside..... Just long enough so it is proud of the surface by 1/2-3/4". (Larger bolts we always use black iron pipe, but this looks pretty small.)
3. Place your tube on top, held with vise grip by a partner, FLAT DOWN AGAINST stuck bolt. Stick your rod inside, and fill with weld..... have that beeswax candle mentioned earlier RIGHT there. Melt it in on the outside.
4. While still hot, remove all with pipe wrench/vise grips.
5. If this does not work, you are "screwed" (pun intended)..... and will need to use aforementioned and pictured portable tap burner. If it does work, you can thank the Guru of broken bolts...... don't become one- it ain't a very appealing title.

Greg in West Mitten

[oldred]

1. Take pencil grinder with carbide flat burr/endmill. Get the top of what is left in there as flat as you can.
2. Make a mild steel tube as thick wall as you can, and still get a welding rod inside..... Just long enough so it is proud of the surface by 1/2-3/4". (Larger bolts we always use black iron pipe, but this looks pretty small.)
3. Place your tube on top, held with vise grip by a partner, FLAT DOWN AGAINST stuck bolt. Stick your rod inside, and fill with weld..... have that beeswax candle mentioned earlier RIGHT there. Melt it in on the outside.
4. While still hot, remove all with pipe wrench/vise grips.
5. If this does not work, you are "screwed" (pun intended)..... and will need to use aforementioned and pictured portable tap burner. If it does work, you can thank the Guru of broken bolts...... don't become one- it ain't a very appealing title.

Greg in West Mitten

I have used that method many times on larger bolts (probably dozens of times on a particular job that happened quite often at work) and even some of the size the OP is dealing with, it does work quite well but I would hesitate to recommend that in this case. First it takes a lot of experience to get it right and we don't know the if the OP is an accomplished welder (he may very well be!) and the consequences of making a mistake here could be disaster! Bear in mind this is a precision machined iron casting likely surface hardened and if the arc strays onto the casting and/or the tube burns through or any other scenario occurs where the weld makes contact with the iron the problem will increase by orders of magnitude. Even a tiny area (especially in the thread area) of the steel welded onto the iron casting will present a major problem, this spot of steel/iron casting mix will be much too hard to remove by anything short of grinding. A small spot of steel weld mixed with cast iron is so hard it can't be cut with any normal cutting tool and will strip the teeth right off of a carbide burr, ask me how I learned this!!!! Add to this the possibility of creating stress in the hardened surface that could easily lead to cracking around the weld area.


Also we have a difference of opinion on trying to remove it while still hot, this is ONLY a difference of opinion and I am not saying you are wrong and I am right just that we apparently see this from different angles. While heating a part to remove a bolt is a very common way to successfully accomplish the task the goal is to heat the surrounding metal while keeping the bolt as cool as possible thus expanding the hole while keeping the bolt from expanding as much as is practical. By heating the bolt from welding it will have expanded in the hole while the cooler surrounding metal will remain much as it was thus resulting in an even tighter fit. Once cooled however the bolt will often become looser than before it was welded due to the crushing effect on rust/debris between the threads while still hot/expanded, some of this effect is apparent immediately but becomes even more so as the bolt shrinks from cooling. Hot bolt expanded in the hole vs shrunk cooled bolt, which should be looser?

Mixing scrap cast iron into the weld puddle to form globs of steel mixed with the high carbon cast iron welded onto a high wear surface was once the way hard facing was done and is still today a very economical way of producing a very highly wear resistant surface. That is providing cracking of this surface won't matter because this method is highly prone to cracking, if the cracking does not matter then this method is much cheaper than using the expensive hard facing rods and often works just as good. However it would be the LAST thing the OP would want to happen to his cast iron lathe bed even on a tiny scale and with a bolt that size the risk of this happening could be more than just slight!